1. Field of the Invention
The present invention relates to a graphic display system permitting the use of the high density characteristics of non-illuminated, semi-graphic displays while also permitting the high information capability of a full functional graphic. The present invention has been found to be particularly useful in the control system panel board art, and hence will be discussed with particular reference thereto. However, the present invention is also applicable to other types of graphic display systems requiring high contrast, high visibility and high resolution display.
2. Description of the Prior Art
Several types of indicator/display systems have been known and used before, and typical examples thereof are shown in U.S. Pat. No. 3,754,245, issued Aug. 21, 1973, to H. O. Peprnik, entitled "SYSTEM INDICATOR BOARD"; U.S. Pat. No. 3,110,020, issued Nov. 5, 1963, to K. W. Abendroth, entitled "TRACT DIAGRAM PANEL FOR RAILWAY TRAFFIC CONTROLLING SYSTEMS"; U.S. Pat. No. 3,530,615, issued Sept. 29, 1970, to B. C. Meyer, entitled "ILLUMINATED DESIGN SET"; U.S. Pat. No. 3,582,927, issued June 1, 1971, to G. Primavera, entitled "POWER NETWORK DISPLAY PANELS AND CONTROLS"; U.S. Pat. No. 3,624,648, issued Nov. 30, 1971, to J. G. Willoughby, entitled "GRAPHIC DISPLAY ANNUNCIATOR"; U.S. Pat. No. 3,754,244, issued Aug. 21, 1973, to R. H. Garrett, entitled "GRAPHIC DISPLAY ASSEMBLY"; publication of Beta Products in "Control Engineering", July, 1975; brochure of Beta Products, Data Sheet 1050GA, February, 1974; and brochure of The Scam Instrument Corporation, Bulletin H667, copyrighted 1967.
Several types of light emitting diode devices have been known and used before, and typical examples thereof are shown in U.S. Pat. No. 3,573,568, issued Apr. 6, 1971, to H. B. Siegel, entitled "LIGHT EMITTING SEMICONDUCTOR CHIPS MOUNTED IN A SLOTTED SUBSTRATE FORMING A DISPLAY APPARATUS"; U.S. Pat. No. 3,711,789, issued Jan. 16, 1973, to E. G. Dierschke, entitled "DIODE ARRAY ASSEMBLY FOR DIODE PUMPED LASERS"; and IBM Technical Disclosure Bulletin, Vol. 10, No. 8, January, 1968, entitled "Visible Light Emitting Diode".
Several types of polarizers have been known and used before, and a typical example thereof is shown in U.S. Pat. No. 2,334,418, issued November 16, 1943, to E. H. Land, entitled "SIGNAL LIGHT CONSTRUCTION".
Several types of photoelectric devices have been known and used before to regulate light, and a typical example thereof is shown in U.S. Pat. No. 3,539,987, issued Nov. 10, 1970, to L. M. Greene, entitled "AUTOMATIC REGULATOR FOR ANNUNCIATOR LIGHTS IN AIRPLANE COCKPITS".
None of this art discloses the combiation of electronic light sources and electronic components mounted to a matrix backboard in alignment with a semi-graphic display, nor the combination of electronic light sources mounted to a backboard in alignment with a semigraphic display wherein there is means for protecting them from interference with each other, nor the combination of electronic components and light sources in a semi-graphic display wherein reflective light is inhibited, nor a display unit capable of mounting directly on a panel, nor combinations of semi-graphic displays and nonreflective techniques in conjunction with light sources, nor the use of opaque silk screening and paint to make a semigraphic display.